Sitemaps keeps erroring on weekly basis

Having a problem with on of my sitemaps

[Joshmc]

The site I do seo for a site that has over 15 sitemaps, but one of the sitemaps keeps having a problem with google downloading it. Google returns cant access the sitemap. It meets the url and size requirements, and when I send it through validators it has no errors. Yet every week it seems to fail again, then when I resubmit it is will be approved for another week before failing again. This is the only sitemap that is doing this.

Any idea if there is a problem here that I can address. Any help is greatly appreciated!

[goodroi]

is it a static file or a dynamically generated sitemap?

[Joshmc]

@goodroi they are dynamically generated

[phranque]

have you tried "Fetch as Googlebot" for that file?
have you looked for clues in your server access/error logs?

[goodroi]

a dynamically generated file explains why it validates one day and after the file updates itself it doesnt validate again. wait till it doesnt validate again and then go through the sitemap to find what line is causing the error.

[Joshmc]

Ok thank you! My sitemap is very large, is there a good way to look through it, as in are there some huge red flags I should check for right off the bat. Thank you so much for your help with this!

[goodroi]

you can use an online sitemap validator. it will identify which line has an issue. after you fix it re-validate it to make sure you dont have multiple issues.

you may want to also break your big sitemap into smaller files. i doubt the size is causing problems but it wont hurt to do this. also it is easier to trouble shoot smaller sitemaps.

[Joshmc]

Ok thanks again, I will try all of this next time mine fails